Aesthetics, image and feedback not only shape perceptions of sustainability but also influence behaviour. 'Ibis has variously been referred to as the ‘Prius Effect’ (Wood & Skates, 2006) and 'Conspicuous Conservation' (Sexton & Sexton, 2011). Since its introduction, the Prius has received two major revisions and a facelift, and, perhaps more importantly, it has received popular support as a responsible vehicle choice for drivers who wish to minimise the impact of their driving on the environment. Leonardo Di-Caprio drives one, as do many of his celebrity friends. The Prius is no longer regarded as a small car, and a new model called the Prius 'c' has filled the gap left by the now somewhat obese standard Prius. It doesn't really look obese, as it has been streamlined further to reduce air resistance, but despite the technologically aesthetic corset it has put on weight. This effect is referred to in the automotive industry as 'The Bloat Law' (Dykes, 2012). The second version is always larger than the first. Perhaps this applies to fields oilier than the automotive industry, but let us continue for a moment with cars. At the other end of the automotive spectrum is the Hummer - a behemoth sport utility vehicle (SUV) favoured by that other behemoth, Arnold Schwarzenegger. So, who costs the environment more - Leonardo or Arnold? According to a 2005 CNW Marketing Research, Leo does (CNW Marketing Research, 2005). Taking into account the full range of energy usage required to conceive, produce, drive and dispose of a car, CNW marketing concluded that the hybrid Prius consumes 1.6 times more energy over its lifetime than the 2 tonne H3 Hummer. Toyota have since responded with their own figures to show that the CNW figures are misleading, and that the assumptions made are not accurate, but nevertheless, the report raises some interesting questions. So we may well ask the question; which mode of transport is the most sustainable? But before we do that, perhaps we should examine what lies behind the question. Do we ask the question because we want ourselves, or other people, to know that we are saving the planet when we are driving? Perceptions of sustainability are important. For the moment, let us assume that it is self-satisfaction.